This invention relates to apparatus for accurately directing a modulated laser beam onto an arcuately curved film surface for high speed data plotting.
In seismic prospecting, it is now possible to obtain quantities of data relative to a vertical section through the earth formations in a data processing format. In this as well as other applications, it is often desirable to obtain an image reproduction from the data for visual analysis and display. Heretofore, several approaches have been employed. For example, in U.S. Pat. No. 3,561,659, a system is illustrated where a modulated laser beam projects data to the exterior surface of a cylindrically curved film. In U.S. Pat. No. 3,441,949, the system's laser beam projects data to a flat film surface. Non-linear scan effects occur where the light is transmitted from a fixed source to the flat surface. It is highly desirable to project the light to a film in a uniform and consistent manner so that the film reflects the data information independently of errors introduced by the mechanical arrangement of the apparatus.